1. Field of the Invention
The present invention relates generally to pinch valves and pertains, more specifically, to improvements providing pinch valves with better performance and greater versatility, enabling effective employment within a wider range of installations, including installations previously not amenable to the use of pinch valves.
Pinch valves have found widespread use wherever it is desired to restrict the flow of fluids in a fluid conducting system. The simplicity of utilizing a flexible tubular valve member which is pinched to restrict the flow of fluids has created a demand for ever more versatile pinch valves adapted for installation in a wider variety of systems.
A primary drawback of current pinch valve constructions is the necessity for providing the flexible tubular valve member of such pinch valves with a length sufficient to enable closing of the valve without imparting undue tensile stresses to the wall of the valve member. As a result, the overall length of a pinch valve suitable for effective operation in a particular fluid conducting system ordinarily has been greater than the overall length of another valve type which can serve in the same system. Accordingly, many systems which require the use of a more compact valve construction have not been amenable to the use of pinch valves.
2. Description of the Related Prior Art
In an effort to reduce the overall length of a pinch valve, while providing the valve member of the pinch valve with the ability to be pinched closed without excessive tensile stresses in the wall of the valve member, various valve member configurations have been suggested for making available an increased length in the wall of the valve member while minimizing the overall length of the valve itself. Thus, pinch valves have been constructed with flexible tubular valve members in the form of sleeves having arched sections, domed sections and other configurations aimed at supplying an increased length in the wall of the tubular member without a concomitant increase in the overall longitudinal length of the pinch valve itself. However, while some of these current constructions accomplish the above-outlined basic objective, many introduce other undesirable characteristics, such as undue turbulence in the flow of fluids through an open valve, and significantly increased dimensions in transverse directions.